MBTA spokesman Joe Pesaturo said the Route 35 bus was traveling near the intersection of Washington Street and Arboretum Road when it was struck at about 9:35 p.m.

When transit police responded, they discovered that the windows in the front of the bus had been fractured by what appeared to be an air powered BB gun. The driver told authorities that he had seen two people standing in a driveway in the area of Archdale Road -- one of which appeared to be holding a firearm.

Pesaturo said on Sunday, a woman reported that she had been struck in the face with an unknown projectile. Police are investigating if the two incidents are connected.

Anyone with information on the incident is urged to call Transit Police at 617-222-1212.